Ecological Assessment and SWOT–AHP Integration for Sustainable Management of a Mediterranean Freshwater Lake

The Mediterranean region is highly vulnerable to environmental and anthropogenic pressures, including climate change, which significantly affect its aquatic ecosystems, especially shallow lakes. This study examines the fish community and ecological quality of Lake Paralimni, a shallow mesotrophic lake in Central Greece that experienced complete desiccation between 1991 and 1996. Using field surveys, fish species composition, abundance, and biomass were assessed, and the lake’s ecological quality was evaluated through the Greek Lake Fish Index (GLFI) alongside an integrated SWOT (strengths, weaknesses, opportunities, threats) and AHP (Analytic Hierarchy Process) analysis. Six fish species from three families were recorded, predominantly native and endemic, with introduced species representing a minor fraction. While GLFI rated the lake’s quality as “Good,” other multi-metric indicators downgraded it to “Moderate”, highlighting the importance of comprehensive assessments. SWOT analysis revealed strengths such as high native biodiversity and legal protection under Natura 2000, but also weaknesses like fluctuating water levels and limited monitoring. Opportunities include sustainable fisheries and conservation efforts, while threats involve climate change, eutrophication, and illegal species introductions. AHP emphasized threats and weaknesses as top priorities. The study recommends hydrological regulation, invasive species control, and long-term monitoring for sustainable lake management and biodiversity conservation.